To determine the dose-response relationship for vitamins E and C in healthy volunteers. To determine whether the combination of vitamins E and C augment their effect on urinary 8-epi PGF. To determine the effect of taking the optimant antioxidant dose of vitamins E and C on free radical generation in smokers and nonsmokers. To determine whether reduction in cholesterol in mild to moderately hyperlipidemic patients reduces urinary 8-epi PGF excretion. To determine whether the correction of Hhcy in individuals with the MTHFR mutation with folic acid reduced urinary 8-epi PGF. To determine whether pretreatment with antioxidant vitamins reduced 8-epi PGF in atherosclerotic plaque as well as its excretion in urine.